I've noticed the same thing and have asked about it in the past without ever receiving a satisfactory answer. Matter of fact I can't recall receiving any answer, but then my memory is going...
![Tongue [:P]](/FSM/CS/emoticons/icon_smile_tongue.gif)
I use Mozilla Firefox as web browser and I can simply right-click on the image and select 'View Image'. For Microsoft IE you have the 'Show Image' thing, but it doesn't work, at least not with your image. I dunno what similar features other browsers might have.
Anyhoo, it only seems to happen with images that are greater in height than in width. 'Tis probably something quirky in the forum software but I dunno fersher 'cuz I ain't no tech boffo...
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